1. Technical Field
The disclosed embodiments are directed generally to the production and assembly of a bent-axis hydraulic, pump or motor having a case and a rotating group.
2. Description of the Related Art
Bent-axis axial piston hydraulic pumps and motors (which will be collectively referred to herein as pump/motors, but with the intent to encompass both bent-axis axial piston pumps and motors even if such may be used primarily or exclusively in applications as solely a pump or motor without reversible operation) are employed in hydraulic hybrid vehicles as Weil as other hydraulic devices. Such pump/motors typically include a rotating group that comprises several rotating components, such as a power shaft, a barrel, a plurality of working pistons reciprocating within bores in the barrel, a tripod between the barrel and power shaft, and a drive plate that connects the working pistons to the power shaft. The rotating group normally resides within a stationary pump motor case which is provided with fluid supply connections and arcane for installation in a vehicle or other device.
In modern manufacturing systems it is often advantageous to assemble a device as a group of two or more subassemblies, with each subassembly being assembled in a different location and then transported to a final assembly location. The different locations may be within the same factory, which may require hand carrying or transportation by shop cart, or in different buildings or different countries, which requires more robust packaging and transportation. However, for hydraulic pump/motors, although there may be benefits in assembling a rotating group as a subassembly, many of the individual parts of a rotating group are only loosely held together and will easily come apart when outside of a pump/motor case, making it difficult to handle or transport as a subassembly. For these reasons, the rotating group is commonly assembled piece by piece within the pump/motor case. This limits flexibility on the assembly line by tying up the pump/motor case assembly for a longer time while the intricate parts of the rotating group are painstakingly placed into the ease one part at a time.